The Secretary [of Health and Human Services] shall provide that in medicare beneficiary notices provided (under section 1806(a) of the Social Security Act,
42 U.S.C. 1395b–7(a)) with respect to the provision of post-hospital extended care services under part A of title XVIII of the Social Security Act [
42 U.S.C. 1395c et seq.], there shall be included information on the number of days of coverage of such services remaining under such part for the medicare beneficiary and spell of illness involved.